SDCL § 47-21-50: Use of electric energy required--Failure to make energy available.

Any member of a cooperative, other than a member which is itself a cooperative, who agrees to use electric energy shall cease to be a member if he does not use electric energy supplied by the cooperative within six months after it is made available to him or if electric energy is not made available to him by the cooperative within two years after he becomes a member, or such lesser period as the bylaws of the cooperative may provide.